Today and specifically in the aeronautic industry, organic matrix composite materials and continuous fibers are used, mainly based upon epoxy resins and carbon fibers in a large variety of structural elements.
As is well known, aeronautic structures demand the integration of several structural elements. For example, the fuselages require the integration of the skin with other structural elements such as the beams, frames or stringers, which poses different types of problems.
An area that is especially problematic is the circumferential joints of the aircraft fuselage skin sections that are manufactured in composite material, both when they are complete fuselage sections, i.e. closed sections in the shape of a “barrel”, and when they are not. In these types of cases, the use of a coupling device (“butt strap”) is known, in the shape of an internal ring that facilitates the abutment of the skin sections.
The coupling devices manufactured in composite material are normally manufactured in separate parts as solid parts of the rectangular section. In document WO 2009/065587 it describes a method for its manufacture, among other issues.
Other types of configurations of those coupling devices are also known, such as the one described in document WO 2009/056319, which is formed by a plurality of segments placed on top with lengthwise holes.
In the known joint arrangements, where two skin sections, the coupling device mentioned in the form of separate parts of the rectangular section, as well as an internal structural element necessary to provide continuity to beams, frames or stringers are involved, it is necessary to use auxiliary parts, which means several problems and specifically greater thickness in the joint area and a non-uniform surface in the support area of the internal structural element.
This invention is aimed at solving those problems.